Frame border corner connecting device for interconnecting a pair of frame border strips of a changeable frame to form a corner of the changeable frame

ABSTRACT

A frame border corner connecting device for interconnecting a pair of selectively lockable frame border strips of a changeable frame so as to thereby form a corner of the changeable frame is provided. The frame border corner connecting device includes a base element having respective sides to which each one of the frame border strips is securable. The frame border corner connecting device also includes a corner cover element movably mounted to the base element for movement between an open position, in which the corner cover element is clear of the path of movement of an item being moved selectively into or out of the changeable frame, and a closed position in which the corner cover element extends at least partially into the path of movement of the item.

BACKGROUND OF THE INVENTION

[0001] The present invention relates to a frame border corner connecting device for interconnecting a pair of frame border strips of a changeable frame to form a corner of the changeable frame, the frame border strips being movable between a closed item retaining position, in which cover members of the frame border strips press against an item disposed in the changeable frame to support the retention of the item in the changeable frame, and an open item release position in which the cover members have been moved out of the plane of the frame for permitting release and exchange of an item in the changeable frame.

[0002] Changeable frames of the type provided with cover members that are snapped into and out of their closed positions are frequently deployed to present, for display to viewers, items such as posters, placards, advertising brochures, or the like. In these conventional changeable frames, the item disposed in the changeable frame for such display is clamped into its place in the changeable frame by the snap lockable cover members and thereby retained in the changeable frame. To exchange the item retained in the changeable frame for a new item to be displayed, the cover members are snapped out of their closed positions outwardly from the plane of the changeable frame and the item can be readily removed from the changeable frame. In order to construct such a changeable frame from individual frame border strips, it is necessary to interconnect the frame border strips to one another at the corner regions of the changeable frame. One possible approach to this involves cutting the frame border strips with mitered corners so that simple connecting means such as, for example, angle pieces, can be used to interconnect the mated mitered corners of the frame border strips at a prescribed angle. This approach necessitates a precise cutting of the frame border strips in order to maintain an exact assembly of the changeable frame without the occurrence at the connecting junction between the abutting frame border strips of irregularities such as, for example, an offset or a gap.

[0003] Another approach simpler than the approach just noted is to dimension the frame border strips at precisely the desired outer dimensions and then to fit these frame border strips together with an interconnecting element to form a changeable frame. One such interconnecting element is described in German patent document G 84 16 300.3. The therein described interconnecting element is configured as a single piece and is comprised of a corner element, which is configured in correspondence with the frame border strip bordering thereagainst, and two connection rails disposed perpendicular to one another and projecting out of the support surfaces which support the frame border strip. The two connection rails are fixedly securable, via securement bolts, in slots formed in the frame border strips. These connecting elements have the disadvantage that, upon the completed assembly of the frame border strips, the connecting elements extend permanently into those openings in the frame border strips which become open in the open position of the covering frame border strips, so that an item which is to be disposed into the changeable frame must always be fitted into the gap formed below each connecting element in order to place the item into the changeable frame as desired.

[0004] A further variation of the above noted connecting element is described in the German patent document G 88 06 432.8. This document describes a connecting element for interconnecting a pair of frame border strips of a changeable frame, the connecting element being formed of two pieces. A base element is comprised of two connecting rails configured as legs extending perpendicularly to one another with each leg being receivable in a correspondingly dimensioned bore in one of the frame border strips for securement thereat via bolts. A covering is disposable on the connecting rails and securable thereto via resiliently biased seating elements. The appearance of the thus formed corner connection can be altered by substitution of one covering for another covering and thus the changeable frame can be accommodated to the particular preferences of the user of the changeable frame. At the same time, it is possible, in connection with the placement into the changeable frame of a new item, such as, for example, a poster, placard, or the like, to remove the covering beforehand and subsequently remount the covering to the connecting elements. Such a removal of the item securing structure is, to be sure, comparatively complicated and the covering, once removed from the connecting rails, is no longer connected to the changeable frame. This can lead to the situation where a person who desires to place a new item into the changeable frame may possibly inadvertently lose the covering, whereby a new covering must be deployed.

SUMMARY OF THE INVENTION

[0005] The present invention offers an improvement over the known art by providing a frame border corner connecting device for interconnecting a pair of frame border strips of a changeable frame to form a corner connection which, when incorporated into the changeable frame, makes possible an uncomplicated placement of items such as, for example, pictures, placards, posters, or the like. Furthermore, the present invention provides a frame border corner connecting device which enhances in a decorative manner the appearance of the frame border strips which are assembled together in forming the changeable frame.

[0006] The frame border corner connecting device, as configured to provide the benefits of the present invention, has a corner cover element mounted on the base element for movement between an open position in which the corner cover element permits clear access to the changeable frame for releasing and exchanging an item therein, and a closed position in which the corner cover element extends at least partially into the item removal path.

[0007] The corner cover element is movably mounted to the base element in the following manner. The corner cover element is mounted such that it can be moved between its open and closed positions. The corner cover element remains mounted to the base element in both of its open and closed positions such that a separation of the corner cover element and the base element from one another, as is required in the operation of known changeable frames, is no longer required. As a result, the corner cover element permits clear access to the changeable frame in its open position—which is a position in which the frame border strips have at the same time been moved outward from their item securing positions—so that it is a particularly simple operation to place items such as, for example, posters, placards, brochures, or the like, into the changeable frame. Once the frame border strips have been snapped back into their item retaining positions and the corner cover element of the frame border corner connecting device has been moved into its closed position, the item placed in the changeable frame is thereupon retained by the clamping action of the corner cover element and the corner cover element extends into the item removal path of the changeable frame and thereby additionally ensures the retention of the item in the changeable frame. The movement of the corner cover element between its open and closed positions can comprise a tipping movement, a swinging movement, a shifting movement, or other similar movements.

[0008] In accordance with a further feature of the frame border corner connecting device of the present invention, the corner cover element partially covers, in its closed position, the cover members of the frame border strips which border the base element, whereby, in contrast, the corner cover element, in its open position, no longer covers the cover members of the frame border strips. The configuration of the frame border corner connecting device in this manner reliably prevents an inadvertent unsnapping of the cover members and, thus, an opening of the changeable frame. In order to unsnap the cover members and thereby release the item retained in the changeable frame such as, for example, a poster, placard, or the like, the corner cover elements of frame border corner connecting devices of the changeable frame, which interconnect pairs of frame border strips in the corner regions of the changeable frame, must first be moved into their open positions in which these corner cover elements no longer cover the cover members of the paired frame border strips. A configuration of the frame border corner connecting device in this manner also offers advantages in the assembly and construction of the changeable frame. In view of the fact that the corner cover elements partially overlie the cover members of the frame border strips which border the frame border corner connecting devices, it is not necessary to form the cover members in a particularly labor intensive manner in order to still satisfy aesthetic appearance demands. Thus, the cover members can merely be shortened such as, for example, by sawing off the excess, without the need to improve, for the sake of the visual appearance of the cover members, the finish of the cut edge of the cover members. Instead, the cut edges of the cover members produced in such a manner are covered in the closed condition of the changeable frame by the corner cover elements and are thus hidden to the viewer. The possibility also exists, in the event that the widths of those regions which are covered in the closed position of the corner cover element yet uncovered in the open position of the corner cover element are selected to be relatively large, to compensate for tolerance variations in the cover members. A highly exact dimensional tolerance of the cover members with respect to their lengths need not be maintained which thereby contributes in a cost favorable manner to the finish work on these cover members. In connection with a configuration of this manner, it is advantageous if the corner cover element is configured in the form of a hollow cap. The contours of the corner cover element are specifically selected such that the contours follow the curvature of the frame border strips which border the frame border corner connecting device and are covered by the corner cover element in the closed position thereof. This contributes, on the one hand, to an attractive appearance and, on the other hand, leads to an especially reliable securement of the changeable frame against undesired opening of the cover members.

[0009] In accordance with another feature of the frame border corner connecting device of the present invention, the frame border corner connecting device includes a detent and catch detent and catch seat assembly by means of which the corner cover element is releasably lockable in its open and/or closed position. Such a detent and catch seat assembly, when it has releasably locked the corner cover element in its closed position, ensures that the corner cover element can only be moved from its closed position to its open position upon the application of a force on the detent and catch seat assembly sufficient to overcome the retaining force exerted by the detent and catch seat assembly in its seated condition. The corner cover element is thus reliably held in its closed position and an inadvertent movement of the corner cover element into its open position is reliably prevented. If a changeable frame is provided with the frame border corner connecting device of the present invention which has a detent and catch seat assembly which releasably locks the corner cover element in its open position, the placement of an item into, or the removal of an item from, the changeable frame is facilitated. Once the corner cover element has moved into its open position, the detent and catch seat assembly releasably locks the corner cover element in this position so that a person attempting to remove an item from, or place an item into, the changeable frame is not constantly hampered by a corner cover element which tends to fall back into its closed position. In a like manner as the releasable locking of the corner cover element in its closed position, the corner cover element, once it is releasably locked in its open position by the detent and catch seat assembly, can only be moved from its open position to its closed position by the application of a force on the detent and catch seat assembly sufficient to overcome the retaining force exerted by the detent and catch seat assembly in its seated condition.

[0010] In accordance with yet further features of the frame border corner connecting device of the present invention, the corner cover element is movable in a translation movement from its closed position into its open position. In this connection, the base element of the frame border corner connecting device is provided with a pair of guide segments extending in spaced parallel relation to one another, each guide segment extending perpendicular to the plane of the changeable frame and having a lengthwise slot formed therein in which a guide track of the corner cover element travels along for guiding of the corner cover element by the guide segments. A frame border corner connecting device of this configuration permits the corner cover element to be moved from its open position into its closed position and vice versa with just a simple push motion. The translation movement of the corner cover element is effected by the cooperative guided movement of the guide track of the corner cover element along the lengthwise slots formed in the guide segments of the base element. It is to be understood that the guide track can alternatively be formed on the base element instead of being formed on the corner cover element and the guide segments with their slots can be formed on the corner cover element instead of being formed on the base element. Corresponding end stop elements can be provided to limit the movement of the corner cover element which is effected by the movement of the guide track along the slots of the guide segments. These end stop elements can be realized in a conventional manner through cooperating stop surfaces formed on the two components moving relative to one another. In this connection, it can be provided that the corner cover element can be moved beyond, for example, a stop element in the direction of its movement toward its open position so that the corner cover element can be released from the base element. A corner cover element can thus be removed from the base element of a frame border corner connecting device and another corner cover element substituted therefor. Such a substitution process may be performed, for example, to exchange a defective component but may also additionally be performed to substitute a corner cover element having a different color, shape, or dimension. This substitution capability affords the user of the frame border corner connecting device of the present invention an increased flexibility in individually configuring the changeable frame. In order to move the corner cover element of the frame border corner connecting device of the present invention over the greatest possible distance in its movement between its open and closed positions without, however, engendering movement to a large degree of the frame border corner connecting device outwardly beyond the outer dimensions of the changeable frame, the slots of the guide segments can extend transversely to the plane of the changeable frame.

[0011] In order to secure the corner cover element in a predetermined position, a resiliently biased seat arm can be disposed between the guide segments, which is configured to engage a corresponding catch structure formed in the guide track of the corner cover element once the seat arm and the catch structure are aligned with one another at a predetermined relative position between the corner cover element and the base element. The predetermined positions can in particular include the open and closed positions of the corner cover element. The catch structure formed in the guide track of the corner cover element is preferably configured as a slot into which a correspondingly dimensioned projection of the seat arm moves upon alignment of the slot and the projection.

[0012] In accordance with an additional feature of the frame border corner connecting device of the present invention, the frame border corner connecting device includes a pair of connectors extending substantially perpendicularly to one another, each from a respective side of the base element and being receivable in a corresponding receiving structure in a respective one of the pair of frame border strips which border the frame border corner connecting device. In this manner, the base element of the frame border corner connecting device can be secured to the bordering frame border strips by insertion of the connectors into the corresponding receiving structures of the frame border strips. In a preferred configuration of these connectors, the connectors have a T-shaped cross sectional profile and are receivable in correspondingly shaped slots having undercuts on the frame border strips.

[0013] In accordance with a further feature of the frame border corner connecting device of the present invention, a stable interconnection of the frame border strips with the frame border corner connecting device can be ensured by providing support surfaces on the base element, each for supporting thereon a portion of a respective one of the pair of the bordering frame border strips. Through such measures, a twisting of the frame border strips is prevented. Moreover, the base element can include abutment surfaces extending substantially perpendicular to the plane of the changeable frames for abutment thereagainst of the frame border strips. These abutment surfaces also contribute to an improved securement of the frame border strips to the frame border corner connecting device.

[0014] In accordance with yet an additional feature of the frame border corner connecting device of the present invention, the base element includes a backing support surface member which lies in the plane of the changeable frame for supporting thereon a portion of an item backing plate and/or an item disposed in the changeable frame. If an item backing plate is used, this plate can be disposed on the backing support surface members of the frame border corner connecting devices and adhered thereto. In this manner, the frame border corner connecting device of the present invention is securely integrated into a stable overall changeable frame configuration.

[0015] In accordance with a further feature of the frame border corner connecting device of the present invention, the base element includes an opening for training a changeable frame mounting element therethrough. In this manner, a changeable frame having the frame border corner connecting device of the present invention can be mounted in an uncomplicated manner on a wall via, for example, bolts, nails, or the like.

BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The object and advantages of the present invention will appear more clearly from the following specification in conjunction with the accompanying schematic drawings, in which:

[0017]FIG. 1 is an exploded perspective view of one embodiment of the frame border corner connecting device of the present invention in its interconnected condition with the end segments of a pair of frame border strips bordering thereagainst;

[0018]FIG. 2 is a perspective view of a portion of a changeable frame having the one embodiment of the frame border corner connecting device of the present invention and showing the corner cover element thereof in its closed position;

[0019]FIG. 2a is a perspective side view of the portion of the changeable frame shown in FIG. 2;

[0020]FIG. 3 is a perspective view of a portion of a changeable frame having the one embodiment of the frame border corner connecting device of the present invention and showing the corner cover element thereof in its open position;

[0021]FIG. 3a is a perspective side view of the portion of the changeable frame shown in FIG. 3;

[0022]FIG. 4a is a sectional view of the one embodiment of the frame border corner connecting device of the present invention and showing a frame border strip secured thereto;

[0023]FIG. 4b is a sectional view of the one embodiment of the frame border corner connecting device of the present invention and showing the corner cover element in its open position;

[0024]FIG. 5a is a perspective view of the base element of the one embodiment of the frame border corner connecting device of the present invention as seen from below;

[0025]FIG. 5b is a perspective view of the base element shown in FIG. 5a as seen from above;

[0026]FIG. 6a is a perspective view of the corner cover element of the one embodiment of the frame border corner connecting device of the present invention as seen from below; and

[0027]FIG. 6b is a side perspective view of the corner cover element shown in FIG. 6a.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0028]FIG. 1 is an exploded perspective view of one embodiment of the frame border corner connecting device of the present invention with the associated bordering end segments of the frame border strips 3 which comprise the borders of a changeable frame. The frame border corner connecting device is comprised of two pieces: a base element 1 and a corner cover element 2 movable relative to the base element 1. The base element 1 is comprised of two interconnecting tabs 4 extending substantially perpendicularly to one another and each having projections 4 a extending along the sides thereof. Support surfaces 5, which border on the interconnecting tabs 4, extend parallel to the plane of the changeable frame. These support surfaces 5 are in turn each respectively bordered by a stop surface 6 extending perpendicular thereto. A support surface 7 extends perpendicular to a pair of support surfaces 8 which are arranged perpendicular to each other. A corner cover guide assembly 9 is formed on the base element 1 whose configuration is described in more detail later in connection with FIGS. 5a and 5 b. The frame border strips 3 which are connected to the frame border corner connecting device 1 to form therewith a corner of the changeable frame each comprise a base profile element 12, a stop surface 13, and a corner cover element 14. A lengthwise slot 16 is formed in the base profile element 12 which includes undercuts 17 and a support surface 15 is also formed on the base profile element 12 which assists in providing backing support to a frame back wall and/or an item to be supported in the changeable frame for display such as, for example, a picture, a poster, a placard, or the like.

[0029] To install the frame border corner connecting device 1, the interconnecting tabs 4 of the base element 1 are inserted into the corresponding lengthwise slots 16 of the base profile elements 12 of the frame border strips 3. As a result of this insertion process, the projections 4 a formed on the interconnecting tabs 4 are seated in the undercuts 17 of the slots 16. Additionally, the undersides of the base profile elements 12 are seated during this installation process onto the layout surface members 5 formed on the base element 1 of the frame border corner connecting device. This seating prevents a twisting of the frame border strips. The frame border strips 3 are in abutment with the stop surface members 6 formed in the base element 1 of the frame border corner connecting device once the frame border corner connecting devices 4 have been fully inserted into the slots 16. In the installed position of the frame border corner connecting device 1 with the frame border strips 3, the backing surface members 15 formed on the base profile elements 12 are in co-planar, surface continuing alignment with the support surfaces 7 formed on the base element 1 of the frame border corner connecting device. The completed installation of four frame border corner connecting devices with four extents of the frame border strips 3 each extending between a respective pair of the frame border corner connecting devices yields a changeable frame having a continuous, endless loop support surface I comprised of the backing surface members 15 of the base profile elements 12 as well as the support surfaces 7 of the base elements 1 of the four frame border corner connecting devices on which a frame back surface can be disposed. The frame back surface can be fixedly secured, for example, by adhesive means onto the base profile elements 12 or, respectively, the base elements 1. In the event that a frame back surface is dispensed with, then, for example, an item with sufficient stiffness can be disposed directly on the support surface 7. This is possible, for example, with placards comprised of stiff paper. To complete the full assembly of the frame border corner connecting devices 1 with the associated frame border strips 3, the corner cover element 2 of each frame border corner connecting device is mounted to the base element 1 thereof. In this connection, a flange 11 of each corner cover element 2 is seated into the guide rails 10 of the corner cover element. The corner cover element is thus movably mounted to the base element 1 in a manner by which the corner cover element can be guided by the corner cover guide assembly 9 and its guide rails 10 between an open position and a closed position.

[0030]FIGS. 2, 2a, 3, and 3 a each show a view of a portion of a changeable frame having the one embodiment of the frame border corner connecting device of the present invention. FIGS. 2 and 2a are each enlarged perspective views of the one embodiment of the frame border corner connecting device of the present invention with the corner cover element 2 thereof in its closed position while FIGS. 3 and 3a are each enlarged perspective views of the one embodiment of the frame border corner connecting device of the present invention with the corner cover element 2 thereof in its open position. The portion of the changeable frame shown in these figures of the drawings is connected to the adjacent frame border corner connecting devices via the frame border strips 3 connected to the base element 1 of the frame border corner connecting devices as well as to the corner cover elements 2 thereof and collectively these elements support a rigid frame back wall 18. The corner cover element 2 shown in FIG. 2 is in its closed position and it can be seen that, in this closed position of the corner cover element 2, the cover members 14, as are shown in broken lines, are partially overlapped by the corner cover element 2. It is thus not possible in this closed position of the corner cover element 2 to open the cover members 14 by swinging them outwardly and thereby permit free removal of an item retained on the changeable frame. As seen in FIGS. 3 and 3a, when the corner cover element 2 is in its open position, the cover members 14 are not otherwise restricted from being swung outwardly from their dispositions in the plane of the changeable frame and can thus be so moved so as to permit free removal of an item retained on the changeable frame. It can be seen in particular in FIG. 3a that the corner cover element 2 in its open position is disposed to the side of the changeable frame as well as above the changeable frame. This disposition of the corner cover element 2 relative to the changeable frame is achieved via a guiding of the corner cover element 2 into its open position along a path which is inclined with respect to the plane of the changeable frame.

[0031] The sidewise and upward offset of the corner cover element 2 in its open position relative to the changeable frame can be seen more emphatically in FIGS. 4a and 4 b which show, respectively, the corner cover element 2 in its closed position and its open position along with the associated frame border strips 3. The inclined guiding of the corner cover element 2 between its closed and open positions can be clearly seen; this inclined guiding permits a translational opening and closing movement of the corner cover element 2 at an angle to the plane of the changeable frame. Moreover, a detent and catch seat assembly 23, which is a part of the guiding structure on the base element 1 which supports a seat arm 20, can be seen in FIGS. 4a and 4 b. The detent and catch seat assembly 23 is supported on the base element 1 in a resiliently biased manner. The seat arm 20 cooperates with the seat slots 19 a and 19 b which are comprised in the guide rails of the corner cover element 2 in that the seat arm 20 seats in a respective one of the seat slots when the corner cover element 2 is in its closed or open position. The seat arm 20 seats into the seat slot 19 a when the corner cover element 2 is in its closed position and the seat arm seats into the seat slot 19 b when the corner cover element 2 is in its open position. Additionally, a projection is formed on the guide rails of the corner cover element 2, which further guides the movement of the corner cover element 2. The projection 21 contacts a stop member 22 on the base element 1 when the corner cover element 2 is moved into its closed position and thereby prevents a further movement of the corner cover element 2 in its closing direction. In the open position of the corner cover element 2, the projection 21 forms, on the portion thereof bordering the seat slot 19 b, an additional stop surface which is in contact with the seat arm 20 of the detent and catch seat assembly 23. In this manner, the movement of the corner cover element 2 in the direction from its closed position toward its open position is constrained. The application of a large force can, to be sure, cause the detent and catch seat assembly 23 to be moved backwards against its resilient bias, whereupon the projection 21 will also slide over the seat arm 20 and the corner cover element 2 will be uncoupled from the base element 1. This uncoupling procedure can be carried out, for example, in the event that the corner cover element 2 is to be exchanged for another corner cover element. Thus, the possibility is available, for example, to install a new corner cover element 2 on an existing base element 1. The new corner cover element 2 can be, for example, a simple replacement corner cover element although the new corner cover element can, as well, vary in color, form and/or dimensions from the corner cover element 2 which is being replaced. In this manner, the frame border corner connecting device of the present invention offers an additional degree of freedom to the user in configuring a changeable frame. In the normal use of the changeable frame—that is, the simple opening and closing of the changeable frame for exchanging a retained item for another item to be retained such as pictures, posters, placards or the like—the projection 21 prevents an uncoupling of the corner cover element 2 from the changeable frame so that the corner cover element 2 will not become lost. Due to the fact that the corner cover element, which can be clearly seen in FIGS. 3, 3a, and 3 b, has been moved into its open position at an angle upwardly and outwardly from the plane of the frame, the corner cover element does not pose an obstacle for the opening and closing movements of the cover members 14 nor for the item to be placed into the changeable frame.

[0032]FIGS. 5a and 5 b each are a perspective view of the base element of one embodiment of the frame border corner connecting device of the present invention as seen from, respectively, below the base element or above the base element. The base element shown in FIG. 5b has an alternate form of the interconnecting tabs 4 which are provided with teeth 4 b. These teeth can be provided in lieu of the smooth outer surfaces of the interconnecting tabs previously described in order to provide an improved tractive hold of the interconnecting tabs 4 when they are inserted into the lengthwise slots in the base element.

[0033] The assembly of the corner cover guide assembly 9 will now be described in greater detail with reference to FIGS. 5a and 5 b. It can be seen that there are a pair of guide segments forming the sides of the corner cover guide assembly 9 and extending substantially perpendicular to the plane of the frame, with each guide segment having a respective guide slot 26 formed therein. The guide slots 26 are dimensioned in correspondence with the dimensions of the guide rails 10 formed on the corner cover element. It can be seen that the resilient biased detent and catch seat assembly 23 with its seat arm 20 is located between the guide segments extending perpendicular to the plane of the frame. The detent and catch seat assembly 23 has a tongue-like configuration and is connected at its small angle portion with the base element. The resilient bias of the detent and catch seat assembly 23 is provided in this one embodiment of the frame border corner connecting device of the present invention by the elasticity of the material selected for the base element 1. It can be further seen in FIGS. 5a and 5 b that openings 24 and 25 are provided through which mounting elements such as bolts, nails, or the like can be extended for securing a connecting element and, thereby, the changeable frame on which such a connecting element is integrated, to a wall or the like.

[0034]FIGS. 6a and 6 b show views of the cap-like corner cover element. The guide rails 10 with the seat slots 19 a and 19 b as well as the projection 21 can be seen in particular in FIG. 6a. It can also be seen in FIG. 6a how the guide rails 10 are connected via a flange 11 to the corner cover element. The flange 11 has a wedge shape such that the guide rails 10 extending along the flange 11 are inclined with respect to the plane of the frame at an inclination corresponding to that of the guide slots 26. It can be seen in FIG. 6b that the corner cover element 2 has an increasing curvature extending from its edge which rises and then falls toward a diagonal overlying the corner cover element. The side contours of the corner cover element correspond to the outer contour of the cover members of the frame border strips which border the frame border corner connecting device so that these side contours of the corner cover element lie on the cover members in the closed position of the corner cover element. It is to be understood that the form of the corner cover element can be correspondingly varied when deployed with bordering frame border strips having cover members of a different contour.

[0035] The components of the one embodiment of the frame border corner connecting device of the present invention described herein are formed of plastic. Thus, for example, the base element and the corner cover element can be formed by plastic injection molding. It is to be understood, however, that the components can be formed o other material such as, for example, aluminum and a similar metal.

[0036] The specification incorporates by reference the disclosure of German priority document 200 07 769.4 of Apr. 28, 2000.

[0037] The present invention is, of course, in no way restricted to the specific disclosure of the specification and drawings, but also encompasses any modifications within the scope of the appended claims. 

What is claimed is:
 1. A frame border corner connecting device for interconnecting a pair of frame border strips of a changeable frame so as to thereby form a corner of the changeable frame, the frame border strips being movable between a closed item retaining position, in which cover members of the frame border strips press against an item disposed in the changeable frame to support the retention of the item in the changeable frame, and an open item release position in which the cover members have been moved out of the plane of the frame for permitting release and exchange of an item in the changeable frame, the frame border corner connecting device comprising: a base element having respective sides to which each one of the frame border strips is securable; and a corner cover element movably mounted to the base element for movement between an open position, in which the corner cover element is clear of the path of movement of an item being moved selectively into or out of the changeable frame, and a closed position in which the corner cover element extends at least partially into the path of movement of the item.
 2. A frame border corner connecting device according to claim 1 wherein, in the closed position of the corner cover element, the corner cover element extends at least partially over the cover members of the pair of frame border strips so as to oppose movement of the cover members out of their closed item retaining positions and, in the open position of the corner cover element, the corner cover element permits movement of the cover members of the pair of frame border strips into their out of plane item release positions.
 3. A frame border corner connecting device according to claim 1 , wherein the corner cover element has the shape of a hollow cap.
 4. A frame border corner connecting device according to claim 1 , and further comprising a detent and catch seat assembly having a seat arm connected to one of the base element and the corner cover element, and a seating structure on the other of the base element and the corner cover element, the seat arm being releasably biased to engage the seating structure upon the disposition of the corner cover element in at least one of its open and closed positions to thereby releasably secure the corner cover element in the respective position.
 5. A frame border corner connecting device according to claim 1 , wherein the corner cover element is movably mounted to the base element by a means for guiding the corner cover element to move in a translation movement between its closed and open positions.
 6. A frame border corner connecting device according to claim 5 , wherein the means for guiding the corner cover element to move in a translation movement includes a pair of guide segments mounted on the base element extending in spaced parallel relation to one another and each extending perpendicular to the plane of the changeable frame and having a lengthwise slot formed therein, and the corner cover element has a guide track which travels along the lengthwise slots of the guide segments for guiding of the corner cover element by the guide segments.
 7. A frame border corner connecting device according to claim 6 , wherein the lengthwise slots of the guide segments each extend transversely to the frame of the changeable frame.
 8. A frame border corner connecting device according to claim 6 , and further comprising a detent and catch seat assembly having a seat arm connected to one of the base element and the corner cover element, and a seating structure on the other of the base element and the corner cover element, the seat arm being releasably biased to engage the seating structure upon the disposition of the corner cover element in at least one of its open and closed positions to thereby releasably secure the corner cover element in the respective position, the seating structure being supported on the corner cover element for movement therewith along a path located intermediate the guide segments, and the seat arm being resiliently biased to engage the seating structure during movement of the seating structure into correspondence with the seat arm.
 9. A frame border corner connecting device according to claim 1 , wherein the base element includes a pair of connectors, each connector extending from a respective side of the base element and being receivable in a corresponding receiving structure in the respective one of the pair of frame border strips to thereby interconnect the base element and the respective frame border strips.
 10. A frame border corner connecting device according to claim 1 , wherein the base element includes support surfaces, each for supporting thereon a portion of a respective one of the pair of the frame border strips.
 11. A frame border corner connecting device according to claim 1 , wherein the base element includes an abutment surface for abutment thereagainst by a respective one of the pair of the frame border strips.
 12. A frame border corner connecting device according to claim 1 , wherein the base element includes a backing support surface for supporting thereon a portion of an item backing surface.
 13. A frame border corner connecting device according to claim 1 , wherein the base element includes an opening for training a changeable frame mounting element therethrough. 